CVE-2026-55450 Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak

What is CVE-2026-55450?

CVE-2026-55450 is a critical vulnerability in Langflow Langflow, published on 23 Jun 2026.

Official description

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow. This can lead to space exhaustion on the server. In addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.

Weakness: CWE-400, CWE-306, CWE-200

Which versions are affected by CVE-2026-55450?

3 open source packages ship an affected version, including langflow. It affects 1 product.

Products include Langflow Langflow.

How do I fix CVE-2026-55450?

Upgrade langflow to 1.9.1 or later.

Is CVE-2026-55450 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55450 exists.

Public exploit code: 1 Nuclei template and 1 proofs of concept on GitHub.

Other vulnerabilities in Langflow Langflow

• CVE-2026-9198 IBM Langflow Code Injection Exploited Critical 9.8
• CVE-2026-0770 Langflow Inclusion of Functionality from Untrusted Control Sphere Exploited Critical 9.8
• CVE-2025-3248 Langflow Missing Authentication Exploited Critical 9.8
• CVE-2025-34291 Langflow Origin Validation Error Exploited Critical 9.4
• CVE-2026-33017 Langflow Code Injection Exploited Critical 9.3

All Langflow Langflow vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-x223-p2gf-v735, PYSEC-2026-224.